Download Nail Patella Syndrome by Emily Aldridge

By Emily Aldridge
NS215G Mendelian and Human Genetics
Nail Patella Syndrome (NPS) Overview
 Also Known as Fong Disease and
Turner-Kieser Syndrome.
Hereditary disorder
Known as an inherited
disorder for over 100 years.
Affects the nails, skeletal
system, and kidneys.
1/50,000 people
Affects males and females
equally.
Occurs in all ethnic groups
Strongest risk for NPS is a
family history.
The Cause of NPS
 Mutated gene LIM Homebox Transcription Factor 1-
Beta (LMX1B).
 Located on the long arm of chromosome 9
 Codes for a protein that is important in organizing
embryonic limb development.
 Inherited in an autosomal dominant manner.
 Possession on only 1 copy of the defected gene is
enough to cause disease.
 Child has 50/50 chance to inherit the disease-causing
mutation.
NPS Symptoms
 Medical signs vary widely
between patients.
 Some don’t display symptoms.
 Discovered to have NPS only
when genetic studies trace
their family history.
 Scientist doing studies to find
out why some people display
symptoms and others don’t.
Nails
 Found in 80 % of NPS Patients
 One or more fingers but rarely




Thumbnail affected by NPS
all.
Affects mostly thumb and index
finger nails.
May be small and concave with
pitting, ridges, splits, and/or
discoloration.
Lunula are sometimes
triangular.
Toenails are less often affected.
Knee Caps
 One or both may be missing or
poorly developed.
 If present likely to dislocate.
 Knees have a square
appearance.
 Beside the knee cap, other
support structures such as
bones, ligaments, and tendons
maybe malformed.
 Since these stabilized the knee
cap, can cause it to be painful
or difficult to walk.
NPS Kneecap
Hip Bones
 80 % of patients have bony
projections called posterior
iliac horns.
 Internal/not obvious unless
detected on x-ray.
 Not associated with any other
disease.
Kidney Disease
 Incidence of Kidney Disease in NPS patients is
approximately 30-50%
 More apparent later in life.
 Should have regular urinalysis to monitor changes in
kidney function.
Feet and
Ankles
Many are born with a club
foot deformities due to
misplacement of tendons
around the foot and ankle.
Detection
 Diagnosis is often made on visual
medical clues such as the abnormalities
of nails and kneecaps.
 Confirmed by x-rays of the affected
bones.
 Prenatal Diagnosis (as of 2001)is not yet
widely available.
 Genetic Testing is available as of early
2001
 Only through research institutes
that are working to further
characterize this disorder.
 Can’t predict which signs will
develop and the severity of the
symptoms.
 Improved genetic tests are
anticipated in the future.
Treatment
 Not usually necessary
 Kidney treated with dialysis or transplant.
 New kidney won’t be affected.
 If walking becomes too painful the patient will have to
resort to a wheelchair.
 Orthopedic surgery may be necessary for congenital (a
condition present at birth)clubfoot.
 Manipulation or surgery to correct hip dislocation.
 Should be screened for scoliosis.
Many people who have
Nail Patella Syndrome
go on to live a normal
and healthy life.
Bibliography

Club Foot Picture. CDC Public Health Image Library.

Dunston, Jennifer A., Tyler Reimschisel, Yu-Qiang Ding, Elizabeth Sweeney, Randy L. Johnson,
Zhou-Feng Chen, and Iain McIntosh. "A neurological phenotype in nail patella syndrome
(NPS) patients illuminated by studies of murine Lmx1b expression." European Journal of
Human Genetics 13 (2005): 330-35.

Lohr, John T. "Nail-Patella Syndrome." HealthAtoZ. 14 Aug. 2006. 26 July 2008
<http://http://www.healthatoz.com/healthatoz/atoz/common/standard/transform.jsp?requ
esturi requestURI=/healthatoz/Atoz/ency/nail-patella_syndrome.jsp

Mansour, Joanne, ed. "What is NPS." Nail Patella Syndrome Worldwide. 26 July 2008
<http://www.nailpatella.org>.

Nail Patella Syndrome. Journal of Medical Genetics.

Wijten, Jan. Nail Patella Syndrome. 6 Dec. 2006.